Grinding machine



1 M. l. MATHEWSON 1,870,857

GRINDING MACHINE Filed June 22. 1927 4 Sheets-Sheet 1 flit/9706071 Aug. 9, 1932.

M. MATHEWSON GRINDING MACHINE Fil'ed June 22 1927 4 Sheets-Sheet 2 z i l I :2. 1 I I llllllll j I Aug. 9, 1932.

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M. l. MATHEWSON GRINDING MACHINE Filed June 22. 19%.?

v 4 Sheets-Sheet 5 Aug. 9, 1932. M. l. MATHEWSON 1,870,857

GRINDING MACHINE Filed June 22. 1927 4 Sheets-Sheet 4 Patented Aug. 9, 1932 I UNITED STATES PATENT OFFICE MAXWELII I. MATHEWSON, OF PROVIDENCE RHODE ISLAND, ASSIGNOR TO BROWN AND SH ARIE MANUFACTURING COMPANY, A. CORPORATION OF RHODE ISLAND GRINDING MACHINE hpplication flled June 22, 1927. Serial n. 200,624.

The invention relates" chines.

The primary object of the invention is to provide in a grinding machine a novel and improved lubricating system for'maintaining at all times a constant and thorough lubrication of the-wheel spindle bearings and other parts of the machine.

With this object in view, the several features of the invention consist in the devices, combinations and arrangements of parts hereinafter described and claimed and togetherwith the advantages to be obtained thereby should be readily understood by one skilled in the art from the following description taken inconnection with the accompanying drawings, in which Fig. 1 is a view in side elevation partly in. section on the line 1-1 of Fig. 3 of a grinding. machine illustrating one to grinding maembodiment of the invention; Fig. 2 is a; view of the machine in front elevation with parts broken away to illustrate particularly the oiling system for the table drive; Fig. 3 is a detail sectional view in front elevation of the grinding wheel spindle taken on the line 3-3 of Fig. 5 showing the radial and end thrust bearings; Fig. 4.- is aview taken on the line Jr-10f Fig. 3; F ig. 5 is a view taken on-the. line 55 of Fig.3 and includes the lubricant overflow reservoir for the spindle bearings; and Fig. 6 is a plan view of the parts shown in Figs. 3, 4 and 5 with the radial thrust bearing caps removed to show the bearing blocks for the spindle. I p The preferred embodiment of the present invention in a grinding machine comprises a fixed frame on which is mounted a work supporting table to slide transversely of the ma; chine and a grinding wheel spindle carriage adapted for movement to and from the work. A deen trough is formed in the frame between the wheel spindle carriage and the work table to carry off the water used in grinding. Inasmuch as the grinding wheel mustbe capable of very fine adjustment with relation to the work. and rotates at comparatively high speeds. the spindle bearings which are mounted on the wheel spindle carriage must be carefully constructed and closely fitted to 0 prevent any possibility of looseness or play -way'to lubricate the change speed and table of the spindle- For this reason and due also to the large size of the rotating parts and the high speed conditions of operation, it is of particular importance to keep the bearings at all times thoroughly lubricated.

The thorough and continuous I lubrication of the wheel spindle bearings is secured by means of an overflow oil reservoir which connects directly with the bearings and is maintained at a level above that of the bearin that they are submerged in oil at all times. The oil from the bearings and from the overflow of. the reservoir is led down through channels more particularly to be described through other parts of the machine to an oil tank in the baseof the machine from which it is pumped up to the overflow reservoir to circulate again through the machine. In order to permit the use of a gravity feed throughout, the oil from the bearings and from the overflow of the reservoir is collected in a fixed portion of the machine immediately beneath the wheel spindle carriage and is conveyed across the water troughin a covered passagedriving mechanism located beneath the work supporting table.

Referring more particularly to the drawings, the grinding machine herein illustrated comprises a grinding wheel- 6 secured to r0- tate on'a spindle 8 which is mounted on a carriage 10 movable on the slideways 12 on the. frame 14 towards and away from the work. A work supporting carriage is indicated at 16 slidably mounted on ways 18 to move transversely. of the'machine. Between the work support and the spindle carriage is a relatively deep trough 19 formed in the frame 14. The s indle 8 is mounted to turn in the fixed bearings indicated at 20 and 22 on the carriage 10 and is held accurately in position by means of the radial bearing blocks indicated at 24,26, and 28. The grinding wheel is' driven through a belt pulley indicated at 30 on the wheel spindle.

In order thatthe bearing blocks may he held securely in position while at the same time permitting their ready adjustment with relation to the spindle. and also to facilitate their removal from the machine, they are 100 provided at each end with trunnions 32 which are adapted to engage in radially situated slots 34 in the fixed portions of the bearings. The bearing blocks are held adjustably in contact with the spindle by compression spring plungers 36 which ress against the radial bearing blocks at points which are on a line with the axis of the trunnions 32. With this arrangement, the bearing blocks maybe held with uniform pressure in contact with the spindle while permitting the blocks to adjust themselves automatically about the axis of the trunnions to fit the contour of the rotating spindle.

Inasmuch as it is usually necessary for the workman to take out and replace the radial bearing blocks several times in fitting the radial thrust bearings, these parts have been constructed and arranged particularly to make them readily accessible. The plungers for the bearing blocks 24 and 26 are, therefore, mounted in a removable cap 38 which is secured to the machine frame by the screw bolts 40, and the plungers for the bearing block 28 are similarly mounted in a removable cap 42. The compression springs 44, coiled within recesses 46 in the plungers and bearing at their outer ends against the cap 38, tend to hold the plungers-yieldingly in engagement with the radial bearing blocks. The plungers 36 may be locked in the position to which they have been adjusted by the springs by means of friction members 47 mounted in the cap adjacent to the plungers and forced into hard frictional contact therewith by means of the set screws 48 as illustrated in Fig. 5.

When the radial bearing blocks are applied to the spindle bearings with suificient pressure to prevent undesirable movement or chatter of the spindle there is a tendency for the leading edge of the bearing block to wipe the rotating spindle dry of lubricating oil with consequent injury to the parts. This diflicul ty has been met in the present instance by locating the axis of the trunnions about which the blocks rotate .to one side of the center of the block, the wider side being placed on that side of the block which the surface of the rotating spindle approaches so that the greater part of the pressure exerted by the spring plungers will fall upon the rear portion of the bearing blocks. A comparatively thick oil film will then be collected under the leading edge o'f'the bearing reducing the danger of wiping the bearing to a minimum while at the same time insuring a sufliclent amount of .011 to prevent rupture of the film as it is thinned by the greater pres-,

sure exerted on the rear portion of the blocks.

End thrust bearings are provided for positioning the spindle as accurately as possible against movement lengthwise in either direction, and automatic spring means are provided for adjusting the hearings to secure 1 required tightness of fit to prevent looseness of the spindle without rupturing the oil film in the bearings. To reduce the effect of expension and contraction of the spindle to a minimum the bearings for taking up the end P thrust in both directions are located at one end of the spindle. The end thrust in one direction is taken up by theengagement of the fixed bearing or bushing 22 with a ring 49 mounted on the spindle between a-shoulder 50 and a nut 51 threaded to the end of the spindle. The end thrust in the opposite direction is taken up by means of a bearing block 52 which is slidably mounted in the wheel a sufiicient degree of tightness without run- P ning the risk of rupturing the oil film in the bearings. After the machine has been sufliciently warmed up, the set screw '62 is tightened up, locking the block 52 in position and thus substituting a fixed bearing for the yielding spring contact.

An automatic lubricating system is provided for insuring a continuous and thorough lubrication of the wheel spindle bearings as well as other parts of the machine. The oil utilized as a lubricant is pumped from the base to a lubricant supply reservoir in the wheel spindle carriage at the top of the machine from where it is conveyed by a gravity feed to the various parts to be lubricated and finally back to the base. The reservoir is con-- nected with the wheel spindle bearings by means of a direct passageway and is provided with an overflow darn which serves to keep the oil in the reservoir at a level above any point in the bearings so that they are at all times completely immersed in oil. Ducts leading from recesses at the ends of the bearings to the wheel spindle carriage ways and to the overflow channel from the reservoir the wheel spindle bearings and an overflowdam is provided at 74 which maintains the oil in the reservoir at a level which is above the highest point in the bearings. A blind duct indicated at draws oil from the recess at one end'of the wheel spindle bearings to lubricate the V-shaped way 12 and similar ducts 76 are provided for the lubrication of the remaining way 12. Oil is also drawn from the wheel spindle bearings into a small reservoir 77 from where it is suppliedthrough a slow drip plug to the feed screw for moving the wheel spindle carriage to and from the In order that the oil may be supplied byv the gravity feed to other parts of the machine, including the change speed gearing and the mechan sm located in the front portion of the machine for driving the work supporting table, the distributing reservoir 84 takes the form of a covered conduit 86 which extends across the relatively deep trough which is provided in machines of this type to carry away the water used in grinding.

The oil in the distributing reservoir 84 is mainta ned at a constant level byan overflow dam 88 from which oil flows to the. change speed gear box 90 and from there through anopening 92 into the reservoir 64 in the base of the machine.

Oil is also drawn off from the distributing reservoir through another channel to lubricate other parts of the table driving and reversing mechanism. In order to insure an adequate supply for this purpose without drawing ofl so much as to lower the level of 1 oil in the distributing reservo r and so interfere with the lubrication of the change speed gears, an outlet pipe 94 is provided with" a small orifice 96 through which the oil flows at a comparatively slow rate. The oil is conveyed through the pipe 94 to an oil pocket 98 in which is mounted the worm gear 100 for the table hand feed. The oil is maintained in the pocket 98 at a level slightly below that of the distributing reservoir 84. From this point the oil drips down through the intermeshing gears 102 into the oil pocket 104 which contains the clutch 106 for throwing the table hand feed into and out of operation,

. and an adjoining oil pocket 108 containing the worm gear 110 and drag mechanism for the table drive. An overflow hole 112 in the side of the pocket 108 maintains the oil in these pockets at the desired height and drains into the reservoir 84 from where it is again pumped to the upper part of the machine.

The construction of radial and end thrust bearings for the grinding wheel spindle which have been illustrated and described herein is the joint invention of the present applicant and Arthur Brown and forms the z subject matter of an application filed of even date herewith.

The invention having been described, what is claimed is:

1. In a lubricating system for a machine tool, the combination of spindle bea rings, a spindle adapted for rotation in the bearin s at relatively high speeds, a lubricant supp y reservoir, a supply connection from the reservoir to the spindle bearings, anoverfiow dam for maintaining the lubricant in the reservoir above the level of the spindle hearings to cause the bearings at all times to be submerged in an oil bath, a'distributing reservoir for collecting the overflow from the supply reservoir and the bearings having a restricted orifice for drawin 01f a portion of the lubricant from the distributing reservoir, channels through which the overflow from the supply reservoir and the bearings is con,

veyed to the distributing reservoir, and an overflow dam for drawing ofi lubricant from the distributing reservoir.

"iii

2. In a lubricating system for a grinding machine, the combination of a Work supporting table, table driving and change speed mechanisms, a grinding'wheel, a grinding wheel spindle, a wheel spindle carriage, spindle bearings, a lubricant supply reservoir mounted on the wheel spindle carriage, a supplyconnection fromthe reservoir to the spindle bearings, meansfor draining off the lubricant seeping through the bearings, an overflow dam in the reservoir to maintain the lubricant in the reservoir above the level of the spindle bearings and cause the bearings at all times to be submerged in an oil bath, a distrbuting reservoir for collecting the overflow from the bearings and the supply reservoir mounted in the fixed portion of the machine, channels for conveying the lubricant from the bearings and overflow dam to said distributing reservoir, and conduits for distributing lubricant from the distributing reservoir to the table driving and change speed mechanisms. i

3. In a lubricating system for a grinding machine, the combination of a fixed frame, a work supporting table, a wheel spindle carriage adapted for movement to and from the work, a water-trough formed in the frame between the table and the carriage, driving and change speed mechanisms beneath the work supporting table, wheel spindle bearings, a lubricant supply reservoir on the wheel spindle carriage, a supply connection from the reservoir to the spindle bearings, means for maintaining the lubricant in the reservoir above the level of the spindle bearings, a distributing reservoir for collecting the lubricant from the bearings and the supply reservoir, and a conduit for the lubricant across the water trough to lubricate the driving and change speed mechanisms.

5 4- In a lubricating system for a grinding machine the combination of a fixed frame, a work supporting table, a wheel spindle carriage adapted for movement to and from the work, a watertrough formed in the frame bem tween the table and the carriage, driving and change speed mechanisms beneath the work supporting table, wheel spindle bearings, a lubricant supply reservoir on the wheel spindle carriage, a supply connection from the reservoir to the spindle bearings, means for maintaining the lubricant in the reservoir above the level of the spindle bearings, a distributing reservoir for collecting the lubricant from the wheel spindle bearings and the supply reservoir in the upper part of the fixed frame and comprising a conduit across the water trough, an overflow dam for maintaining a constant level in the distributing reservoir, means for conveying lubricant from the overflow dam to the change speed mechanism, and a conduit having a restricted passage for drawing a portion of the lubricant from the distributing reservoir for the table driving mechanism.

3o 5. In a lubricating system for a machine tool, the combination of spindle bearings, a spindle adapted for rotation in the bearings at relatively high speeds, a lubricant supply reservoir on/ substantially the same plane with the spindle bearings, a supply connection from the reservoir to the spindle hearings to permit lubricant to flow freely between the reservoir and the bearings, an overflow dam for maintaining the lubricant in the reservoir above the level of the spindle bearings, to

cause the bearings at all times to be submerged in an oil bath, a distributing reservoir for collecting the oil from the bearings and the supply reservoir having a restricted orifice for drawing ofi a portion of the lubricant from the distributing reservoir, channels for conveying the lubricant from the bearings and overflow dam to said distributing reservoir,

and anoverflow dam for drawing off lubricant from the distributing reservoir.

6. In a lubricating system for a grinding machine, the combination of a fixed frame, a work supporting table, table driving and change speed mechanisms, a grinding wheel, a grinding wheel spindle, a wheel spindle carriage, wheel spindle bearings, a water trough formed in the frame between the table and the carriage, means for supplying lubricantto the spindle bearings, a'distributing reservoir. for collecting the lubricant in a fixed portion of the machine, a conduit form;- ing an extension of the reservoir across the water trough, and conduits for distributing lubricant from the distributing reservoir to the table driving and change speed mechanisms.

7 In a lubricating system for a grinding machine, the combination of a fixed frame, a work supporting table, a grinding wheel spindle, a wheel spindle carriage adapted for movement to and from the work, a water trough formed in the frame between the table and the carriage, driving and change speed mechanisms beneath the work supporting table, wheel spindle bearings, means for supplying lubricant to the spindle bearings, a distributing reservoir mounted in the fixed frame beneath the wheel spindle carriage for collecting the lubricant, and a conduit for the lubricant across the water trough to lubricate the driving and change speed'mechanisms.

8. In a lubricating system for a grinding machine, the combination of a fixed frame,

.a work supporting table, a grinding wheel spindle, a wheel spindle carriage adapted for movement to and from the work, a water trough formed in the frame between the table and the carriage, driving and change speed mechanisms beneath the work support ing table, wheel spindle bearings, means for supplying lubricant to the spindle bearings, a distributing reservoir mounted beneath the wheel spindle carriage for collecting the lubricant in the upper part of the fixed frame and comprising a conduit across the water trough, an overflow dam for maintaining a constant level in the distributing reservoir, means for conveying lubricant from the overflow dam to the change speed mechanism, and a conduit having a restricted passage for drawing a portion of the lubricant from the distributing reservoir for the driving mechaniSm. 9. In a lubricating system for a machine tool, the combination of a fixed frame, a carriage mounted for horizontalmovement on the frame, spindle hearings on the carriage, a 4 spindle adapted to rotateat high speeds in no the bearings, a lubricant supply reservoir on the carriage, a supply connection from the reservoir to the spindle bearings to permit the lubricant to flow freely between the reservoir yd the bearings, an overflow dam in the reser oir to maintain the lubricant in the reser oir above the level of the spindle bearings and cause the bearings at all times to be submerged in an oil bath, a distributing reservoir in the machine frame for collecting and redistributing to otherparts of the machine the overflow from the supply reservoir and the bearings, channels for conveying lubricant from the overflow dam to the distributing reservoir, outlets from the distribu: ting'reservoir for distributing lubricant to other parts of the machine, and means for supplying lubricant to the supply reservoir.

10. In a lubricating systemvfor a grinding machine, the combination of a fixed 1 frame, a work support, a grinding wheel, a grinding wheel spindle, a wheel spindle carriage movable on the base with relation to the work support, a lubricant supply reservoir, a supply connection from the reservoir to the spindle bearings to permit lubricant to circulate freely between the reservoir and the bearings, and overflow dam to maintain the lubricant in the reservoir above the level of the spindle bearings and cause the bearings at all times to be submerged in an 'oil bath, a distributing reservoir in the fixed frame for collecting and redistributing to other parts of the machine the overflow from the supply reservoir and the bearings, channels for conveying lubricant from the bearings and the overflow dam to the distrib uting reservoir, outlets from the distributing reservoir for distributing lubricant to other 2 parts of the machine, a well in the frame to which the lubricant is finally drained, and means for returning the lubricant from the well to the supply reservoir.

11. In a lubricating system for a grinding machine, the combination of a work supporting table, a grinding wheel, a grinding wheel spindle, a wheel spindle carriage including 5 indle bearings movable toward and away rom the 'work table, a lubricant supply reservoir in the wheel spindle carriage on substantially the same plane with the spindle bearings, a supply connection from the reservoir to the spindle bearings, an overflow dam in the reservoir to maintain the lubricant in the reservoir above the level of the spindle bearings and cause the bearings at all times to be submerged in an oil bath, a distributing reservoir in the fixed portion of the machine for collecting the 40 lubricant from the overflow dam and the spindle bearing, channels for conveying lubricant fromthe overflow dam and the bearing to the distributing reservoir outlets from the distributing reservoir to distribute lubricant to other parts of the machine, a reservoir in the base of the machine from which lubricant is supplied to the whole machine and a pump for pumping lubricant from said reservoir to the supply reservoir in the wheel spindle carriage.

In, testimony whereof I have signed my name to this specification.

MAXWELL I. MATHEWSON. 

